Eerie problem with compiler... need help

[Tophurious]

So I posted this before, but got no answer. I found a way around it but now my backway is doing the same problem.

Basically, in one of my get methods:

Property Get H() As Double
    H = CalcH 'This was implemented as the "Back Way" and it fixed problem, before the code in CalcH was in here
End Property

Private Function CalcH() As Double
    If pH <= 0# And pT > 0# And pP > 0# Then 'calculate if not set
        pH = STMPTH(pP, pT)
    ElseIf pH <= 0# And pT > 0# Then
        If pType = StreamType.Water Then
            pH = STMTQH(pT, 0#)
        Else
            pH = STMTQH(pT, 1#)
        End If
    ElseIf pH <= 0# And pP > 0# Then
        If pType = StreamType.Water Then
            pH = STMPQH(pP, 0#)
        Else
            pH = STMPQH(pP, 1#)
        End If
    End If
    CalcH = pH
End Function

When I run the program, I give pH a value of 1488. But when it comes to retrieving that value the compiler goes nuts. If I run the program, I get "Error 6: Overflow". So I use the debugger, I step through the WHOLE program... and it completes its run with no issue.... so I run again... and get the error. I find out it is when I retrieve the H value. So I put a break right there. I run program to the break and then step through the retrieval and find something quite odd. When it gets to the

If pH <= 0# And pT > 0# And pP > 0# Then 'calculate if not set

it actually returns true... but pH has a value of 1488! so I do this again and mouse over the pH to see what it says and it says "pH = 0" thats odd... I hit F8 to step. then mouse over pH, still "pH = 0" I open up the locals window and locate the pH variable. it says "pH = 1488", I mouse over pH again and now it says "pH = 1488" BUT IT JUST PASSED AN IF STATEMENT SAYING IF<=0!!!! please help!

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[pureenhanoi]

So I posted this before, but got no answer. I found a way around it but now my backway is doing the same problem.

Basically, in one of my get methods:

Property Get H() As Double
    H = CalcH 'This was implemented as the "Back Way" and it fixed problem, before the code in CalcH was in here
End Property

Private Function CalcH() As Double
    If pH <= 0# And pT > 0# And pP > 0# Then 'calculate if not set
        pH = STMPTH(pP, pT)
    ElseIf pH <= 0# And pT > 0# Then
        If pType = StreamType.Water Then
            pH = STMTQH(pT, 0#)
        Else
            pH = STMTQH(pT, 1#)
        End If
    ElseIf pH <= 0# And pP > 0# Then
        If pType = StreamType.Water Then
            pH = STMPQH(pP, 0#)
        Else
            pH = STMPQH(pP, 1#)
        End If
    End If
    CalcH = pH
End Function

When I run the program, I give pH a value of 1488. But when it comes to retrieving that value the compiler goes nuts. If I run the program, I get "Error 6: Overflow". So I use the debugger, I step through the WHOLE program... and it completes its run with no issue.... so I run again... and get the error. I find out it is when I retrieve the H value. So I put a break right there. I run program to the break and then step through the retrieval and find something quite odd. When it gets to the

If pH <= 0# And pT > 0# And pP > 0# Then 'calculate if not set

it actually returns true... but pH has a value of 1488! so I do this again and mouse over the pH to see what it says and it says "pH = 0" thats odd... I hit F8 to step. then mouse over pH, still "pH = 0" I open up the locals window and locate the pH variable. it says "pH = 1488", I mouse over pH again and now it says "pH = 1488" BUT IT JUST PASSED AN IF STATEMENT SAYING IF<=0!!!! please help!

i saw that you are programing about Class. I've never seen this type of error before. But i think problem here is caused by Local Varriables and Global Varriables. Can u discribe more about ur Class. ( Member Varriables and Member Function)

[Killer42]

I can't look at the images right now, because my work system blocks them. Will have a look in a few hours when I'm at home. In the meantime...

Are you setting it to 1488 or 1488# ? Perhaps there's an unintended conversion happening somewhere along the line, which is causing a calculation to overflow. VB, along with some other languagesw, has a nasty tendency to convert everything in a calculation to match the smallest data type used anywhere in the calculation. This can really screw you up sometimes.

Like I said, I'll have a look at this in detail in a few hours, and see whether anything comes to mind.

[Tophurious]

Private pP As Double 'Pressure of the stream
Private pT As Double 'Temperature of the stream
Private pH As Double 'Enthalpy of the stream
Private pW As Double 'Flow of the stream
Private pType As StreamType 'Type of stream: Steam, Water, Leak(Enum)
Private pName As String 'Name of the stream

Property Let P(P As Double)
    pP = P
End Property

Property Let T(T As Double)
    If pType = Steam And pP <> 0 Then
        If (T - STMPT(pP)) < 27 Then 'Check for 27 degree superheat per PTC 6
            pT = 0
        Else
            pT = T
        End If
    Else
        pT = T
    End If
End Property

Property Let H(H As Double)
    pH = H
End Property

Property Let W(W As Double)
    pW = W
End Property

Property Get P() As Double
    P = pP
End Property

Property Get T() As Double
    If pT = 0 And pH > 0 And pP > 0 Then 'calculate if temp unknown & H known
        If Not SuperHeat Then
            pT = STMPHT(pP, pH)
        End If
    End If
    T = pT
End Property

Property Get H() As Double
    H = CalcH
End Property

Property Get W() As Double
    W = pW
End Property

Property Get SType() As StreamType
    SType = pType
End Property

Property Get Name() As String
    Name = pName
End Property

Property Get S() As Double 'Get Entropy
    If pT <> 0 And pP <> 0 Then
        S = STMPTS(pP, pT)
    ElseIf pT = 0 And pP <> 0 Then
        S = STMPHS(pP, H)
    End If
End Property

Property Get x() As Double 'Get X
    x = STMPHQ(pP, H)
End Property

Property Get Q() As Double 'Get Energy Flow Rate (H*W)
    Q = H * pW
End Property

Property Get V() As Double 'Get Specific Volume
    V = STMPTV(P, T)
End Property

Property Get Density() As Double 'Get Specific Density
    If P = 0 Then
        Density = 62.087 + 0.022519 * T - 0.00033873 * (T ^ 2) + 0.0000010579 * (T ^ 3)
    Else
        Density = 1 / V
    End If
End Property

Property Get C() As Double 'Get Specific Heat
    C = 1.0244 - 0.00071715 * pT + 0.0000061796 * (pT ^ 2) - 0.000000016397 * (pT ^ 3)
End Property

This problem went away. And KEEPS COMING BACK!!! I switched my computers out and it started working again. Now I have the same sort of issue and we tried it on 3 different computers here. same problem. I run the program and get overflow. but I can hold down F8 for 20 minutes and easily fly past the point at which it crashes. I am so tired of it. I want to use C# or C++ but unfortunately my company does not have licenses for it.

[pureenhanoi]

This problem went away. And KEEPS COMING BACK!!! I switched my computers out and it started working again. Now I have the same sort of issue and we tried it on 3 different computers here. same problem. I run the program and get overflow. but I can hold down F8 for 20 minutes and easily fly past the point at which it crashes. I am so tired of it. I want to use C# or C++ but unfortunately my company does not have licenses for it.

i tried copy ur code in to a new project and do it. No problem occured. Maybe, u have other statement that i dont know. But i have small idea.

Property Let H(H As Double)
      pH = H
End Property

Here, u let pH = H. H maybe a local varriable in proprerty Let. If this is, no problem occure. But if VB translate H as Property Get H() As Double that u declare. So, this is wrong. I donot ensure how VB translate this, but u shouldnt use the same name for the varriable as the Property name.
Use the same name for Property Let and Property Get only.

Property Let H ([U]hValue[/U] as Double)
     pH = hValue
End Property
Property Get H () As Double 
     H = calH()
End Property

Try replacing other Varriables which name as similar as Property name and do ur project again. If it still have error, i must say sorry because i cannot help u any more.

[Killer42]

That is some weird stuff you've got going on there.

Sorry, I completely forgot about it. I'll e-mail myself a reminder to have a look when I get home tonight.

In the meantime, one straw you could grasp in desperation is to put DefDBL A-Z at the top of the module(s), to indicate a default data type of Double for everything. Probably won't help, but hey, it probably won't hurt.

[Killer42]

Just a note. As I think on it further, it's not really all that surprising that things can work slightly differently between compiled and interpreted code. After all, if the problem is related to temporary values generated during a calculation, there's no reason why the runtime and IDE code couldn't be using some slightly different code internally to do it.

My guess is that it will probably just end up being necessary to force something to Double format, or split up a calculation (or comparison) to gain finer control over the format conversions. However, I haven't read back through the whole of the thread yet. Will do so tonight.

In the meantime, good luck!

[Killer42]

Well, I've had a look through the images. I'm going to admit complete bafflement. I've never really done much with classes, and I know things can get complicated due to different memory models, different types of creation/sharing/destruction of objects and so on. For all I know, there might be another instance of something which is working with the same data that you are looking at.